The unit of rate of reaction and rate of rate constant are same for a :

Options

A. zero order reaction
B. first order reaction
C. second order reaction
D. third order reaction

Explanation

To solve the question regarding the unit of the rate of reaction and the rate constant being the same for a specific order of reaction, we can follow these steps:

### Step 1: Understand the Definitions
- The **rate of reaction** is defined as the change in concentration of a reactant or product per unit time, typically expressed in mol/L/s (molarity per second).
- The **rate constant (k)** is a proportionality constant in the rate law that relates the rate of reaction to the concentration of reactants.

### Step 2: Write the Rate Law
For a general reaction of order **n**, the rate law can be expressed as:
\[ R = k [A]^n \]
where:
- \( R \) is the rate of reaction,
- \( k \) is the rate constant,
- \([A]\) is the concentration of the reactant,
- \( n \) is the order of the reaction.

### Step 3: Determine Units for Different Orders
1. **Zero Order Reaction (n = 0)**:
- Rate: \( R = k \cdot [A]^0 = k \cdot 1 = k \)
- Units: Rate = mol/L/s, Rate constant \( k \) also has units of mol/L/s.

2. **First Order Reaction (n = 1)**:
- Rate: \( R = k \cdot [A]^1 = k \cdot [A] \)
- Units: Rate = mol/L/s, Concentration = mol/L, thus \( k \) has units of s\(^{-1}\).

3. **Second Order Reaction (n = 2)**:
- Rate: \( R = k \cdot [A]^2 \)
- Units: Rate = mol/L/s, Concentration = mol/L, thus \( k \) has units of L/mol/s.

4. **Third Order Reaction (n = 3)**:
- Rate: \( R = k \cdot [A]^3 \)
- Units: Rate = mol/L/s, Concentration = mol/L, thus \( k \) has units of L²/mol²/s.

### Step 4: Compare Units
From the above analysis:
- For a **zero order reaction**, the units of rate and rate constant are both mol/L/s.
- For **first, second, and third order reactions**, the units of rate constant differ from the units of rate.

### Conclusion
The unit of the rate of reaction and the rate constant are the same for a **zero order reaction**.

### Final Answer
**The correct option is: Zero Order Reaction.**

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